ECU LEXUS SC400 1991 Service Workshop Manual

INSTALL FRONT AIRBAG SENSOR
Install the sensor with the arrow on the sensor facing toward
the front of the vehicle.
Torque: 25 NVm (260 kgf Vcm, 19 ft Vlbf)
NOTICE:
wMake sure the sensor is installed to the specified torque.
wIf the sensor has been dropped, or there are cracks, dents
or other defects in the case, bracket or connector, replace
the sensor with a new one.
wThe sensor set bolts have been anti±rust treated. When
the sensor is removed, always replace the set bolts with
new ones.
wAfter installation, shake the sensor to check that there is
no looseness.
wThe front sensor is equipped with an electrical
connection check mechanism. Be sure to lock this
mechanism securely when connecting the connector. If
the connector is not securely locked, a malfunction code
will be detected by the diagnosis system.
wCheck that the dimensions of the body where the front
airbag sensor is installed match those in the body
dimension drawings on page BO±133.
(The airbag may malfunction, or may not work, if the
mounting angle or dimensions of the sensor mount
are not correct.) AB±17
SRS AIRBAG
± Removal and Installation of Component Parts
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(MAIN POINTS OF REMOVAL AND
INSTALLATION)
CAUTION: Work must be started after approx. 20 se-
conds or longer from the time the ignition switch is
turned to the LOCK position and the negative (±) terminal
cable is disconnected from the battery (See page AB±2).
NOTICE:
wDo not open the cover or the case of the ECU and various
computers unless absolutely necessary. (If the IC termi-
nals are touched, the IC may be destroyed by static elec-
tricity.)
wNever use airbag parts from another vehicle. When
replacing parts, replace with new parts.
wNever reuse the center airbag sensor assembly involved
in a collision when the airbag has deployed.
wNever repair a sensor in order to reuse it.
REMOVE AND INSTALL CENTER
AIRBAG SENSOR ASSEMBLY
(a) Using a torx wrench, loosen and tighten the three screws.
Torx wrench: T40 (Part No. 09042±00020 or locally manufac-
tured tool)
Torque: 13 N Vm (130 kgf Vcm, 9 ft Vlbf)
NOTICE:
wMake sure the sensor assembly is installed to the speci-
fied torque.
wIf the sensor assembly has been dropped, or there are
cracks, dents or other defects in the case, bracket or
connector, replace the sensor assembly with a new one.
wWhen installing the sensor assembly, take care that the
airbag wiring does not interfere with other parts and is
not pinched between other parts.
wAfter installation, shake the sensor assembly to check
that there is no looseness.
(b) Disconnect the connector. AB±19
SRS AIRBAG
± Removal and Installation of Component Parts
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CLEARING OF DIAGNOSTIC CODE
1. CLEARING OF MALFUNCTION CODE(EXCEPT CODE 41)
Remove the battery negative (±) terminal or ECU±B fuse for
10 seconds or more with the ignition switch OFF.
NOTICE: When connecting the battery after cancelling
the malfunction code, always do it with the ignition
switch in LOCK position. If the battery is connected with
the ignition switch in ACC or ON position, there are cases
when the diagnosis system does not operate normally.
HINT:
wCode 41 cannot be cleared by this method.
wThe lower the temperature, the longer the battery
negative (±) terminal must be left off.
wOther memory systems (clock, audio system) will also
be cancelled out (See page AB±2).
2. CLEARING OF MALFUNCTION CODE 41 STORED IN MEMORY
(a) Connect service wires to terminals Tc and AB of theTDCL.
(b) Turn the ignition switch ACC or ON and wait approx. 6 seconds.
(c) S ta rtin g with th e Tc te rmin a l, ap p ly bo d y gr ound
alternately to terminal Tc and terminal AB twice each in
cycles of 1.0 ± 0.5 seconds. Finally, keep applying body
ground to terminal Tc.
HINT: When alternating between body ground of terminals Tc
and AB release one from body ground while applying it to the
other terminal. The time interval in between must be within
the following conditions. If it is out of the conditions, code 41
will not be cleared.
(d) After several seconds, when the airbag warning light
starts to blink in a 64 msec. cycle, cancellation is
completed.
HINT: This method clears not only code No. 41, but also other
malfunction codes all at once.
Except when instructed by the troubleshooting procedure,
use this method only when the repair procedure is completed
(See page AB±25).
AB±32
SRS AIRBAG
± Troubleshooting
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Wiring Diagram
CENTER AIRBAG SENSOR ASSEMBLY CONNECTOR
No.SymbolTerminal NameNo.SymbolTerminal Name
18E2Ground
2±SRRH Front Airbag Sensor (±)9LAAirbag Warning Light
3+SRRH Front Airbag Sensor (+)10D±Squib (±)
4+SLLH Front Airbag Sensor (+)11D+Squib (+)
5±SLLH Front Airbag Sensor (±)12TcDiagnosis
6+BBattery (ECU±B Fuse)13E1Ground
7IG2Power Source (IGN Fuse)14AccPower Source (CIG Fuse)
AL1Electrical Connection Check
MechanismBL2Electrical Connection Check
Mechanism
AB±33SRS AIRBAG ± Troubleshooting
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AT00S±01
PRELIMINARY CHECK
1. CHECK FLUID LEVELHINT:
wDrive the vehicle so that the engine and transmission
are at normal operating temperature.
Fluid temp.: 70±80 5C (158±176 5F)
w Only use the COOL range on the dipstick as a rough
reference when the fluid is replaced or the engine does
not run.
(a) Park the vehicle on a level surface and set the parking brake.
(b) With the engine idling and the brake pedal depressed, shift the shift lever into all positions from P to L position and return
to P position.
(c) Pull out the transmission dipstick and wipe it clean.
(d) Push it back fully into the tube.
(e) Pull it out and check that the fluid level is in the HOT range. If the level is at the low side, add fluid.
Fluid type:
ATF TYPE T±II or Equivalent
NOTICE: Do not overfill.
2. CHECK FLUID CONDITION If the fluid smells burnt or is black, replace it.
3. REPLACE TRANSMISSION FLUID
(a) Remove the drain plug and drain the fluid.
(b) Reinstall the drain plug securely.
(c) With the engine OFF, add new fluid through the oil filler tube.
Fluid type:
ATF TYPE T±II or Equivalent
Capacity:
Total: 8.2 liters (8.7 US qts, 7.2 lmp. qts)
Drain and refill: 1.9 liters (2.0 US qts, 1.7 lmp. qts)
(d) Start the engine and shift the shift lever into all positions fromP to L position and then shift into P position.
(e) With the engine idling, check the fluid level. Add fluid up to the
COOL level on the dipstick.
±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±47
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AT±66
IN±33
WIRING DIAGRAM
O/D Cancel Signal Circuit
CIRCUIT DESCRIPTION
While driving with cruise control activated, in order to minimize gear shifti\
ng and provide smooth cruising
when driving uphill, overdrive may be prohibited temporarily in some conditions.The cruise control ECU
sends O/D cut signals to the ECM as necessary and the ECM cancels overdrive s\
hifting until these signals
are discontinued.(For details, see the cruise control system, on BE sectio\
n).
DIAGNOSTIC CHARTDIAGNOSTIC CHART
AT±116±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTING
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NGOK
NGOK
OKNG
INSPECTION PROCEDURE
1Check voltage between terminal OD1of ECM connector and body ground.
C
OK
P1. Connect the check harness A to the ECM (See EGsection).
2. Turn ignition switch ON.
Measure voltage between terminal OD1 of ECM con-
nector and body ground.
Voltage: 4 ± 6 V
Proceed to next circuit inspection shown on matrix chart
(See page AT±66).
2Check voltage between terminal OD of cruise control ECU harness side con\
nector and body
ground.
C
OK
P1. Disconnect cruise control ECU connector.
2. Turn ignition switch ON.
Measure voltage between terminal OD of cruise control
ECU harness side connector and body ground.
Voltage: 4 ± 6± V
Check and replace cruise control ECU.
3Check harness or connector between cruise control ECU and ECM (See page\
IN±33).
Repair or replace harness or connector.
Check and replace ECM.
±
A304E (1UZ±FE) AUTOMATIC TRANSMISSION TROUBLESHOOTINGAT±117
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13. INSTALL GLASS(a) Position the glass so that the reference marks are linedup, and press in gently along the rim.
(b) Using a spatula, apply adhesive on the glass rim.
(c) Use a scraper to remove any excess or protruding adhesive.
(d) Fasten glass securely until the adhesive sets.
14. INSPECT FOR LEAKS AND REPAIR (a) P e rfo rm a le a k te st afte r th e ha r dening time has
elapsed.
(b) Seal any leak with auto glass sealer.
Part No. 08833±00030 or equivalent
15. INSTALL WINDSHIELD MOULDINGS
(See steps 1 to 4 on pages BO±98 to 99)
16. INSTALL COWL LOUVER (a) Put the louver in the glass.
(b) Install four clips.
(c) Install weatherstrip.
17. INSTALL WIPER ARMS
BO±50
±
BODY Windshield
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10. INSTALL GLASS(a) Position the glass so that the reference marks are linedup, and press in gently along the rim.
(b) U s e a s p a t u l a t o r e m o v e a n y e x c e s s p r o t r u d i n g adhesive.
(c) Fasten glass securely until the adhesive sets for about 24 hours.
11. INSPECT FOR LEAKS AND REPAIR (a) P e rfo rm a le a k te st afte r th e ha r dening time has
elapsed.
(b) Seal any leak with auto glass sealer.
Part No. 08833±00030 or equivalent
12. INSTALL FOLLOWING PARTS: (a) Back window lower moulding
(b) Luggage compartment door
(c) Package tray trim
(d) Roof side inner garnish
(e) Rear seat back and cushion
±
BODY Back Window GlassBO±57
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BODY DIMENSIONS
Description
1. BASIC DIMENSIONS(a) There are two types of dimensions in the diagram. (Three±dimensional distance)
wStraight±line distance between the centers of two
measuring points.
(Two±dimensional distance)
wHorizontal distance in forward/rearward between the centers of two measuring points.
wThe height from an imaginary standard line.
(b) In cases in which only one dimension is given, left and right are symmetrical.
(c) The dimensions in the following drawing indicate actual
distance. Therefore, please use the dimensions as a
reference.
2. MEASURING (a) Basically, all measurements are to be done with atracking gauge. For portions where it is not possible to
use a tracking gauge, a tape measure should be used.
(b) Use only a tracking gauge that has no looseness in the body, measuring plate, or pointers.
HINT:
1. The height of the left and right pointers must be equal.
2. Always calibrate the tracking gauge before measuring or after adjusting the pointer height.
3. Take care not to drop the tracking gauge or otherwise shock it.
4. Confirm that the pointers are securely in the holes.
(c) When using a tape measure, avoid twists and bends in
the tape.
(d) When tracking a diagonal measurement from the front
spring support inner hole to the suspension member
upper rear installation hole, measure along the front
spring support panel surface.
±
BODY Body Dimensions (Description)BO±127
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